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I was using "intersect" in my Matlab code to do the sorting where I want the following:

[ch] = sort(s, 'ascend'); 

[same, a] = intersect(s, ch);

For example:

input:

s = [55 21 78 7]

output:

ch = [7 21 55 78]
a = [4 2 1 3]

I need to access a where a shows the original index prior to sorting so I can use it for further processing.

This method works exactly as what I want, but I guess it is taking a lot of time to do the sorting and intersect etc especially when the size of s approaching 100 or higher, are there faster or smarter ways to do so?

Thank you very much.

marsei
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user2563812
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1 Answers1

1

You can achieve this with 

[ch IX] = sort(s, 'ascend')

where IX is identical to a.

marsei
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